Struct McpServer 

pub struct McpServer { /* private fields */ }

In-process MCP server that owns registered tools, resources, and prompts.

Implementations

impl McpServer

pub fn new( server_name: impl Into<Cow<'static, str>>, server_version: impl Into<Cow<'static, str>>, ) -> Self

Create a dynamic MCP tool server with the advertised metadata.

pub fn builder( server_name: impl Into<Cow<'static, str>>, server_version: impl Into<Cow<'static, str>>, ) -> McpServerBuilder

Start building a dynamic MCP tool server with generated registrars.

pub fn from_tool_registry( server_name: impl Into<Cow<'static, str>>, server_version: impl Into<Cow<'static, str>>, tools: McpToolRegistry, ) -> Self

Create a dynamic MCP server from an existing tool registry.

pub fn tool_registry(&self) -> &McpToolRegistry

Borrow the shared tool registry.

pub fn tool_registry_mut(&mut self) -> &mut McpToolRegistry

Mutably borrow the shared tool registry.

pub fn into_tool_registry(self) -> McpToolRegistry

Consume the server and return its tool registry.

pub fn add_tool<Call>( &mut self, definition: ToolDefinition, call: Call, ) -> Result<(), McpToolError>

where Call: Fn(McpToolCall) -> ToolCallResult + Send + Sync + 'static,

Register a synchronous MCP tool handler.

Errors

Returns McpToolError when definition is invalid or a tool with the same name is already registered.

pub fn add_typed_tool<Input, Call>( &mut self, definition: McpTypedTool<Input>, call: Call, ) -> Result<(), McpToolError>

where Input: McpToolInput, Call: Fn(Input) -> ToolCallResult + Send + Sync + 'static,

Register a synchronous typed MCP tool handler.

Errors

Returns McpToolError when definition is invalid or a tool with the same name is already registered.

pub fn add_tool_async<Call, Fut>( &mut self, definition: ToolDefinition, call: Call, ) -> Result<(), McpToolError>

where Call: Fn(McpToolCall) -> Fut + Send + Sync + 'static, Fut: Future<Output = ToolCallResult> + Send + 'static,

Register an async MCP tool handler.

Errors

Returns McpToolError when definition is invalid or a tool with the same name is already registered.

pub fn add_typed_tool_async<Input, Call, Fut>( &mut self, definition: McpTypedTool<Input>, call: Call, ) -> Result<(), McpToolError>

where Input: McpToolInput, Call: Fn(Input) -> Fut + Send + Sync + 'static, Fut: Future<Output = ToolCallResult> + Send + 'static,

Register an async typed MCP tool handler.

Errors

Returns McpToolError when definition is invalid or a tool with the same name is already registered.

pub fn list_tools(&self) -> Vec<ToolDefinition>

Return registered MCP tool definitions.

pub fn contains_tool(&self, name: &str) -> bool

Whether a tool name is already registered.

pub fn tool_count(&self) -> usize

Number of registered tools.

pub fn add_resource<Read>( &mut self, definition: ResourceDefinition, read: Read, ) -> Result<(), McpToolError>

where Read: Fn() -> ReadResourceResult + Send + Sync + 'static,

Register a static MCP resource reader.

Errors

Returns McpToolError when definition is invalid or a resource with the same URI is already registered.

pub fn add_resource_async<Read, Fut>( &mut self, definition: ResourceDefinition, read: Read, ) -> Result<(), McpToolError>

where Read: Fn() -> Fut + Send + Sync + 'static, Fut: Future<Output = Result<ReadResourceResult, ErrorData>> + Send + 'static,

Register an async MCP resource reader.

Errors

Returns McpToolError when definition is invalid or a resource with the same URI is already registered.

pub fn add_resource_template( &mut self, definition: ResourceTemplateDefinition, ) -> Result<(), McpToolError>

Register an MCP resource template advertised by resources/templates/list.

Errors

Returns McpToolError when definition is invalid.

pub fn list_resources(&self) -> Vec<ResourceDefinition>

Return registered MCP resource definitions.

pub fn list_resource_templates(&self) -> Vec<ResourceTemplateDefinition>

Return registered MCP resource template definitions.

pub fn contains_resource(&self, uri: &str) -> bool

Whether a resource URI is already registered.

pub fn resource_count(&self) -> usize

Number of registered concrete resources.

pub fn add_prompt<Get>( &mut self, definition: PromptDefinition, get: Get, ) -> Result<(), McpToolError>

where Get: Fn(Option<JsonObject>) -> GetPromptResult + Send + Sync + 'static,

Register a static MCP prompt.

Errors

Returns McpToolError when definition is invalid or a prompt with the same name is already registered.

pub fn add_prompt_async<Get, Fut>( &mut self, definition: PromptDefinition, get: Get, ) -> Result<(), McpToolError>

where Get: Fn(Option<JsonObject>) -> Fut + Send + Sync + 'static, Fut: Future<Output = Result<GetPromptResult, ErrorData>> + Send + 'static,

Register an async MCP prompt.

Errors

Returns McpToolError when definition is invalid or a prompt with the same name is already registered.

pub fn list_prompts(&self) -> Vec<PromptDefinition>

Return registered MCP prompt definitions.

pub fn contains_prompt(&self, name: &str) -> bool

Whether a prompt name is already registered.

pub fn prompt_count(&self) -> usize

Number of registered prompts.

pub fn call_tool(&self, name: &str, arguments: Option<Value>) -> ToolCallResult

Calls a registered tool and converts validation or handler failures into a protocol-level tool result.

pub async fn call_tool_async( &self, name: &str, arguments: Option<Value>, ) -> ToolCallResult

Asynchronously calls a registered tool and converts validation or handler failures into a protocol-level tool result.

pub async fn serve_stdio(self) -> ServeStdioResult

Serve this server over stdin/stdout using the MCP stdio transport.

Errors

Returns an error when stdio serving fails or the service task fails.

pub fn serve_stdio_blocking(self) -> ServeStdioResult

Serve this server over stdin/stdout on a new Tokio runtime.

Errors

Returns an error when the Tokio runtime cannot be created, stdio serving fails, or the service task fails.

Trait Implementations

impl Clone for McpServer

fn clone(&self) -> McpServer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl ServerHandler for McpServer

fn get_info(&self) -> ServerInfo

fn list_tools( &self, _request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListToolsResult, ErrorData>> + MaybeSendFuture + '_

fn get_tool(&self, name: &str) -> Option<Tool>

Get a tool definition by name.

fn call_tool( &self, request: CallToolRequestParams, _context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CallToolResponse, ErrorData>> + MaybeSendFuture + '_

Handle a tools/call request from a client.

fn list_resources( &self, _request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListResourcesResult, ErrorData>> + MaybeSendFuture + '_

fn list_resource_templates( &self, _request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListResourceTemplatesResult, ErrorData>> + MaybeSendFuture + '_

fn read_resource( &self, request: ReadResourceRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ReadResourceResponse, ErrorData>> + MaybeSendFuture + '_

fn list_prompts( &self, _request: Option<PaginatedRequestParams>, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<ListPromptsResult, ErrorData>> + MaybeSendFuture + '_

fn get_prompt( &self, request: GetPromptRequestParams, _context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetPromptResponse, ErrorData>> + MaybeSendFuture + '_

fn ping( &self, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

fn initialize( &self, request: InitializeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<InitializeResult, ErrorData>> + MaybeSendFuture

fn negotiate_initialize( &self, request: &InitializeRequestParams, ) -> Result<InitializeResult, ErrorData>

Build the initialize response for request, negotiating the protocol version against Self::supported_protocol_versions.

fn supported_protocol_versions(&self) -> Cow<'static, [ProtocolVersion]>

Return the protocol versions supported by this server.

fn discover( &self, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<DiscoverResult, ErrorData>> + MaybeSendFuture

Return this server’s discovery information.

fn complete( &self, request: CompleteRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CompleteResult, ErrorData>> + MaybeSendFuture

fn set_level( &self, request: SetLevelRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

fn accepted_subscription_filter( &self, requested: &SubscriptionFilter, ) -> Option<SubscriptionFilter>

Return the subset of a requested notification filter this server accepts.

fn listen( &self, context: SubscriptionContext, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

Run one established subscription until it is cancelled or closed gracefully.

fn subscribe( &self, request: SubscribeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

👎Deprecated:

resources/subscribe is legacy-only; implement accepted_subscription_filter and listen for protocol version 2026-07-28

fn unsubscribe( &self, request: UnsubscribeRequestParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

👎Deprecated:

resources/unsubscribe is legacy-only; subscriptions/listen is cancelled through its request lifecycle

fn on_custom_request( &self, request: CustomRequest, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<CustomResult, ErrorData>> + MaybeSendFuture

fn on_cancelled( &self, notification: CancelledNotificationParam, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

fn on_progress( &self, notification: ProgressNotificationParam, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

fn on_initialized( &self, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

fn on_roots_list_changed( &self, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

fn on_custom_notification( &self, notification: CustomNotification, context: NotificationContext<RoleServer>, ) -> impl Future<Output = ()> + MaybeSendFuture

fn get_task( &self, request: GetTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<GetTaskResult, ErrorData>> + MaybeSendFuture

SEP-2663 tasks/get: return the current DetailedTask state.

fn update_task( &self, request: UpdateTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

SEP-2663 tasks/update: accept responses to outstanding in-task input requests. Returns an empty acknowledgement on success.

fn cancel_task( &self, request: CancelTaskParams, context: RequestContext<RoleServer>, ) -> impl Future<Output = Result<(), ErrorData>> + MaybeSendFuture

SEP-2663 tasks/cancel: cooperative cancellation. Returns an empty acknowledgement; the task’s observable status may lag.